In 1962, boxing writers and fans considered Cassius Clay an obnoxious self-promoter, and few believed that he would become the heavyweight champion of the world. But Malcolm X, the most famous minister in the Nation of Islam-a sect many white Americans deemed a hate cult-saw the potential in Clay, not just for boxing greatness, but as a means of spreading the Nation's message. The two became fast friends, keeping their interactions secret from the press for fear of jeopardizing Clay's career. Clay began living a double life-a patriotic "good Negro" in public, and a radical reformer behind the scenes. Soon, however, their friendship would sour, with disastrous and far-reaching consequences. Based on previously untapped sources, from Malcolm's personal papers to FBI records, Blood Brothers is the first book to offer an in-depth portrait of this complex bond. Acclaimed historians Randy Roberts and Johnny Smith reconstruct the worlds that shaped Malcolm and Clay, from the boxing arenas and mosques, to postwar New York and civil rights-era Miami.